Among the dozens of booths at Kush Con II over the weekend at the Colorado Convention Center, it was easy to spot the common items -- glass pieces, 420 T-shirts and the like -- but new ways to make money off the burgeoning marijuana industry here have cropped up, too.

Like "Prescription Lock," a tray that keeps your pot -- or you know, anything that can fit in a prescription bottle -- locked up and safe. Take one guess who inventor Mike Moldal sees as his target market: parents of teenagers.

Moldal also notes that the invention can be used by caregivers of those who look after elderly patients, although one could argue that octogenarians can and should be able to get high whenever they want to. Their grandkids are another matter, he notes.

Prescription Lock on display at Kush Con II.

"Teens are our primary market," says Moldal, the president and CEO of the company, which is based in Lone Tree.

The invention will be available to the public in spring 2011, Moldal says, adding that he hopes to see it at pharmacy mega-chains like Walgreens. For now though, medical marijuana-smoking parents will have to continue to hide their joints between those Deep Purple and Frank Zappa LPs in the den.